Purity ≥ 90%, as determined by SDS-PAGE under reducing conditions and visualized by silver stain.Endotoxin: ≤ 1EU/1ug. Noelin-1 (neuronal olfactomedin-related endoplasmic reticulum-localized-1), also known as olfactomedin-1 or pancortin, is a 75kD\ secreted extracellular matrix glycoprotein expressed in the brain.1-3 Alternate promoter usage and splicing creates four forms of Noelin (Noelin 1-4) that are combinations of a common central region with alternate N and C termini.3, 4 Noelin-1 is the longest of the four isoforms, encoding a 16 amino acid (aa) signal sequence and a 469 aa mature protein with a coiled coil region for multimerization and an olfactomedin-like domain. The shortest isoforms, Noelin-3 and -4, are truncated within the coiled-coil region and lack the olfactomedin-like domain.4 In the species tested, these isoforms appear to oppose actions of the longer isoforms.5 All isoforms are capable of forming homo- or heterodimers through cysteines in their common central regi